Electric power distribution cables are commonly routed underground in manholes, vaults and tunnels. These environments are characterized by limited space and close positioning between adjacent electrical utility cable circuits. As such, the electrical cables must be securely maintained in controlled position so as to ensure proper spacing between the cables so that they do not interfere with one another, while affording workers sufficient space to carry out maintenance tasks and additional installation. While the aforementioned enclosures are generally closed and to a certain extent sealed, the environment within these enclosed spaces contains moisture and humidity. Indeed, many of these underground enclosures are subject to frequent flooding, as well as breaches by underground pests, sewage and corrosive elements.
When housed in an underground enclosure, electrical power cables should be maintained in an elevated position above the enclosure's floor for maintenance purposes. These types of cables are typically engaged and supported by cable racks capable of withstanding the range of temperatures encountered in these types of environments, as well as the moisture and humidity associated with these subterranean enclosures. The underground cable support racks are typically comprised, at least in part, of metal components which are subject to galvanic and stray current corrosion. This type of corrosion is capable of damaging or destroying metal electrical cable support structures possibly resulting in electrical power interruption. These electrically conductive metal racks also constitute a safety hazard to workers tending to the manhole, vault or tunnel.
U.S. Pat. Nos. 8,960,612 and 8,733,560 disclose cable support systems which include support members comprised of reinforced polymers and are intended for use with communication cables. These cable support systems are unable to accommodate the large expansion characteristics of current electrical utility distribution cables having a 3-1/c spiral configuration. Current electrical utility cable saddles are required to have the capability to limit cable movement to the cable's longitudinal axis along its length and prevent lateral cable movement which can cause cable joint failure.
The present invention addresses, in general, environmental conditions encountered by electric cables located underground, and is particularly directed to a nonmetallic support arrangement for securely maintaining electrical cables in a fixed, elevated position in an underground structure such as a manhole, vault or tunnel. The present invention is particularly directed to a lightweight, non-metallic, cantilevered cable support bracket adapted for secure, direct coupling to a support structure-mounted stanchion without the need for conventional couplers, such as screws or nut and bolt combinations. The present invention accommodates movement of an electrical cable(s) in manholes arising from its load cycle in directions primarily along its length, and only slightly transverse movement to the cable's longitudinal axis.